1. Field of the Invention
The present invention relates to an image reading apparatus, and more particularly, an image reading apparatus which reads images recorded on an image recording material such as a photographic photosensitive material.
2. Description of the Related Art
A photographic film may be scratched on an emulsion surface or a back surface (the surface opposite the emulsion surface) depending on how the film is handled. When a photographic film has a scratch on a portion that corresponds to an image recording area and an image recorded on the photographic film is output (i.e., the image is recorded on a recording material such as photographic printing paper, or displayed on a displaying means such as a display), the scratch on the photographic film is often, depending on the size, depth or type of the scratch, clearly visible on the output image as a defect portion, such as a low density streak or a white streak. Also, when a photographic film has foreign matter such as dust on the surface, the foreign matter is clearly visible on an output image as a defect portion.
A surface exposure type photographic printing apparatus, which exposes and records an image onto photographic printing paper by irradiating a photographic film with light such that light transmitted through the photographic film irradiates the photographic printing paper, includes a diffusion plate disposed between a light source and the photographic film and irradiates the photographic film with light diffused by the diffusion plate, as a countermeasure for scratches on the photographic film. However, with the above-described technique, defects in an output image (the image exposed and recorded on photographic printing paper) are only slightly reduced (the defect portions only become slightly less obtrusive).
As a technique applicable to an image reading apparatus which reads an image recorded on a photographic film by a reading sensor such as a CCD, Japanese Patent Application Laid-Open (JP-A) No. 11-75039 has disclosed a technique of reading a photographic film with at least four lights corresponding to four wavelength ranges (three wavelength ranges of visible light and one wavelength range of invisible light, for example, infrared or ultraviolet), and correcting image information obtained by visible light readings on the basis of information obtained by an invisible light reading.
Amounts of visible light transmitted through the photographic film vary with image density of an image recorded on the photographic film, and are also varied at a portion of the photographic film having a scratch or foreign matter because a portion of the visible light irradiated to the portion of the photographic film is refracted or reflected at the portion of the photographic film. On the other hand, although amounts of invisible light transmitted through the photographic film vary at the portion of the photographic film having the scratch or foreign matter, the amounts are not affected by density of the image recorded on the photographic film.
Therefore, in accordance with the technique described in JP-A No. 11-75039, by detecting scratches and foreign matter on the photographic film on the basis of variations in amounts of invisible light transmitted through the photographic film, corrections for variations in amounts of visible light transmitted through the photographic film, which variations are due to scratches and foreign matter on the photographic film, i.e., corrections for defect portions in an image (an image represented by image information obtained by visible light readings) caused by the scratches and foreign matter on the photographic film, can be made with assurance.
To read an image recorded on a photographic film with high accuracy, it is desirable to read the image preliminarily at a relatively low resolution (pre-scanning), determine reading conditions on the basis of results of pre-scanning, and then read the image finally at a relatively high resolution (fine-scanning) under the determined reading conditions. However, in the technique described in JP-A No. 11-75039, optimal timing of reading with invisible light when two readings, pre-scanning and fine-scanning, are performed is not considered.
For example, when two readings, pre-scanning and fine-scanning, are performed, reading with invisible light may be performed during both pre-scanning and fine-scanning. In such a case, by performing a reading with invisible light during pre-scanning, status of defect portions can be tested, for example, during an image test carried out on the basis of an image displayed on a display or the like and, by performing a reading with invisible light during fine-scanning, defect portions can be detected with high accuracy and highly accurate corrections can be made, because the reading is performed at a high resolution. However, a problem with reading with invisible light during both of pre-scanning and fine-scanning is that reading takes a long time.
As described above, timing of reading with invisible light greatly affects accuracy of correction for defect portions and reading speed. However, required levels of accuracy of correction for defect portions, reading speed and the like when reading an image often differ between individual cases. For example, there are cases in which high reading speed is desired but high accuracy of correction for defect portions is not required. Conversely, there are cases in which a high quality image whose defect portions are corrected with high accuracy is desired even if reading speed is slow.
The present invention is intended to solve the above-described problems, and the first object of the present invention is to provide an image reading apparatus which detects defect portions in an image and can reduce reading time.
The second object of the present invention is to provide an image reading apparatus which can perform image reading so as to satisfy various requirements.
A first aspect of the present invention, to accomplish the first object, is an image reading apparatus including a reader which reads an image recorded on an image recording material; a detector which irradiates the image recording material with first light in an invisible region and detects second light in the invisible region which is one of the first light transmitted through and reflected from an image recording area in which the image is recorded; and a controller which effects control such that a preliminary reading of the image is performed by the reader, after which detection of the second light in the invisible region is performed by the detector, after which, and a fine reading of the image is performed by the reader under reading conditions determined on the basis of information obtained by the preliminary reading.
In the first aspect of the present invention, the reader reads the image recorded on the image recording material, and the detector detects the light transmitted through or reflected from the image recording area of the image recording material in which the image is recorded (the second light). Thereby, defect portions due to scratches or foreign matter in the image recording area of the image recording material can be detected on the basis of result of detection of the second light by the detector. Further, image data for which defect portions due to scratches and foreign matter on the image recording material have been corrected can be obtained by, for example, correcting image data obtained by reading of the image by the reader on the basis of results of detection of the second light by the detector.
Further, in the first aspect of the present invention, the controller effects control of the reader and the detector so as to perform the detection of the second light by the detector after the preliminary reading by the reader is performed, and then to perform the final reading (fine reading) by the reader. That is, detection of the second light by the detector can be performed only once, thereby reducing image reading time. When detection for defect portions due to scratches or foreign matter on the image recording material is carried out on the basis of results of detection of the second light in invisible region by the detector, detection of defect portions on the basis of results of the detection of the second light in invisible region can be carried out in parallel with the final reading by the reader. Therefore, in the first aspect of the present invention, image reading time of the image reading apparatus which detects defect portions in an image can be reduced.
A second aspect of the present invention is the first aspect of the present invention, wherein the controller starts detection of the second light in the invisible region by the detector before determination of the reading conditions has finished.
When invisible light (the first light) irradiates the image recording area, the amount of invisible light transmitted through or reflected from the image recording area of the image recording material (the second light) is not affected by image density of the image recorded on the image recording material. Therefore, detection of the second light by the detector can be carried out before reading conditions for the final reading are determined, on the basis of information obtained by the preliminary reading by the reader, or during computation of the reading conditions. Thus, in the second aspect of the present invention, the control means starts detection of the second light in invisible region by the detector after the preliminary reading is performed by the reader and before the determination of the reading conditions for the final reading is finished (during computation of the reading conditions and the like). Because detection of the second light by the detector can be carried out in parallel with computation of the reading conditions, reading time of the image reading apparatus can be reduced.
A third aspect of the present invention is the first aspect of the present invention, wherein the fine reading and detection of the second light in the invisible region by the detector are performed at a same resolution.
In the third aspect of the present invention, because the final reading and detection of the second light in invisible region by the detector, as described for the first aspect of the present invention, are performed at the same resolution, there will be no difference between resolution of image data obtained by the final reading by the reader and resolution of data representing results of detection of the second light in invisible region by the detector. Therefore, defect portions can be corrected without correction errors being generated due to a difference between resolutions, and defect portions (defect portions in image data due to scratches and foreign matter) can be corrected with assurance.
A fourth aspect of the present invention, to accomplish the second object, is an image reading apparatus including a reader which reads an image recorded on an image recording material; a detector which irradiates the image recording material with first light in an invisible region and detects second light in the invisible region which is one of the first light transmitted through and reflected from an image recording area in which the image is recorded; an input section for inputting information that instructs whether or not detection of the second light in the invisible region by the detector is performed and, if detection of the second light in the invisible region is to be performed, information that instructs an execution timing of the detection of the second light in the invisible region; and controller which effects control such that a preliminary reading of the image is performed by the reader, after which a fine reading of the image is performed by the reader under reading conditions determined on the basis of information obtained by the preliminary reading and, if the detection of the second light in the invisible region has been instructed via the input section, effects control such that the second light in the invisible region is detected by the detector at at least one of the preliminary reading and the fine reading in accordance with the instructed execution timing.
In the fourth aspect of the present invention, the reader reads the image recorded on the image recording material and the detector detects the invisible light transmitted through or reflected from the image recording area of the image recording material (the second light). Thereby, defect portions due to scratches or foreign matter in the image recording area of the image recording material can be detected on the basis of results of detection of the second light by the detector. Further, image data for which defect portions due to scratches and foreign matter on the image recording material have been corrected can be obtained by, for example, correcting image data obtained by reading of the image by the reader on the basis of results of detection of the second light by the detector.
The controller effects control such that the preliminary reading of the image is performed by the reader, after which the fine reading of the image is performed by the reader under the reading conditions determined on the basis of information obtained by the preliminary reading, and, if the detection of the second light has been instructed via the input section, effects control such that the second light is detected by the detector at at least one of the preliminary reading and the fine reading in accordance with the instructed execution timing by the input section.
For example, in a case in which a high quality image whose defect portions are corrected with high accuracy is desired even if time taken for image reading is long, if information instructing performance of detection of the second light by the detector both at the preliminary reading and at the final reading (fine reading) is input via the inputting means, defect portion correction conditions can be tested on the basis of results of detection of the second light by the detector at the preliminary reading, for example, during an image test performed on the basis of an image displayed on a display or the like. On the basis of results of the test, highly accurate correction based on results of detection of the second light by the detector at the final reading can be carried out. As a further example, in a case in which accuracy of correction for defect portions is not required even if the high quality image could not be obtained, if information canceling detection of the second light by the detector both at the preliminary reading and at the final reading is input via the inputting means, the readings are carried out without performance of detection of the second light by the detector both at the preliminary reading and at the final reading. Therefore, time taken for image reading can be reduced.
Thus, in the fourth aspect of the present invention, because detection of the second light by the detector is controlled in accordance with information instructing whether or not detection of the second light by the detector is to be performed and the execution timing of detection, which information is input via the input section, image reading can be carried out so as to satisfy various requirements.
When the first, second and third aspects of the present invention are applied to an image reading apparatus which reads an image recorded on a photographic photosensitive material, reading time can be reduced by an invention as described below.
An image reading apparatus including a reader which reads a plurality of images recorded on a photographic photosensitive material; a detector which irradiates the photographic photosensitive material with invisible light and detects invisible light, which light is one of transmitted through and reflected from an image recording area in which an image is recorded; and a controller which effects control such that after a preliminary reading by the reader is performed for the image, reading conditions for a final reading are computed on the basis of information obtained by the preliminary reading and, after detection of the invisible light, which light is one of transmitted through and reflected from the image recording area, by the detector is performed for the image, the final reading is performed for the image by the reader under the computed reading conditions.